Female-to-male shift of mouthbrooding in a cichlid fish, Tanganicodus irsacae, with notes on breeding habits of two related species in Lake Tanganyika

Parental-care patterns and mating systems of three goby-like cichlids in Lake Tanganyika were investigated. In Tanganicodus irsacae females mouthbrooded eggs and small young for about two weeks and then males took over the role for about one week. Field observations of tagged fish suggest that this species is monogamous: a male's home range largely overlapped with that of its mate, while their home ranges were segregated from those of similar-sized consexual adults. Eretmodus cyanostictus also performed female-to-male shift of mouthbrooding and appeared to be monogamous. The third species, Spathodus marlieri, however, exhibited exclusively maternal mouthbrooding. The differences in parental care and mating system among the three species are discussed in relation to their feeding habits, and the pattern of monogamy in the goby-like cichlids is compared with those of other fishes.